Sbs 2003 - pfn_list_corrupt

I'm currently having a problem on a 2003 sbs server.
The server has been running fine for months and there have been no recent driver changes. Windows auto update was enabled.

I'm currently looking into a ram change, but I was hoping someone could look into the mini dup output attached to this post. In case it would look obvious it's not RAM.
My feeling is it's it still one of the printer drivers acting up, but the blue screen shows no sys file, so I wouldn't know which one would be the problem. While I had the printer spooler disabled, no blue screen occured, but I could not do this long enough to draw a proper conclusion.

I would appreciate someone having a look at the dumps attached. I would also like to learn more about how I would go to analyse this information myself.
If anyone can post some links on that.